Roadside pollution in Hong Kong Central hit a record high in August 2012. This full broadsheet page graphic looks at air quality of every hour in the year. Each day is represented by a row of 24 squares, one for each hour.

The idea was to give the reader an overview of the year to see the clear or unhealthy periods, while also offering the opportunity to dig a little deeper into the more granular data. Wind direction is also included to highlight spells when air is carried south from the industrial areas of neighbouring Shenzhen, China.

By Simon ScarrSouth China Morning Post

A closer look

The shade of the square indicates the pollution reading at Central monitoring station.

Hong Kong’s air pollution is often blamed on its proximity to mainland China’s industry. Wind direction each day is included as small arrows to the left of each row in order to gauge the relationship between northerly winds and bad air.

Some text pointers were added to explain probable contributing factors to clearer air.